It seems that version 15.20 no longer makes PHP info exploit links. I have an install still running 15.19 and 15.17 and both are still working for these sites and makes over 500 links.
Version 15.20 literally makes zero links now. In the logs it shows the following: https://www.screencast.com/t/ShaV3N8C4Oo
Those same urls are all successful on previous versions. Hope you can fix it.